OT: Ceres more interesting than previously thought

[Suicide Junkie]

Oh, and as for the radiation thing... It shouldn't take too much water to block the rads.

What if you just build a double-coin, and fill the space between them with water?

As a bonus, that water barrier will help shield the inside habitat from small asteroid impacts. AND keep the sun-facing surface cool!
You can then let the coin face the sun if you like.

Alternatively, what if you set your coin so that it is not quite edge-on to the sun? Align it so the shadow of the sun-ward dirt bottom does not fall on the far edge of the coin.

At "noon" you'd see the sun just to the left of the skyring.
At midnight, you'd get a few rays glancing up from below only if you are on the far right side of the ring.

[NullAshton]

What if you design a material to only let the visible light spectrum, and lower through?

[narf poit chez BOOM]

Beware the mutant fish of DOOM!

I'd use some of that material to build some floating islands.

[dogscoff]

What if you design a material to only let the visible light spectrum, and lower through?

That would be handy- not only for the coin but for spaceships and stuff as well.
I remember a short story involving a ship manufacturer who builds all ships completely transparent, and then the buyer just paints in the bits they want covered. Might have been asimov...

Suicide Junkie said:
Oh, and as for the radiation thing... It shouldn't take too much water to block the rads.

Cool. I know I read somewhere that water is a cool rad blocker.

What if you just build a double-coin, and fill the space between them with water?

Well you could, but then you start getting into "why not just build a giant space station" territory.

As a bonus, that water barrier will help shield the inside habitat from small asteroid impacts. AND keep the

Well, only until the outside barrier gets busted by the first strike and leaks out all the water, surely..?

sun-facing surface cool!
You can then let the coin face the sun if you like.

Alternatively, what if you set your coin so that it is not quite edge-on to the sun? Align it so the shadow of the sun-ward dirt bottom does not fall on the far edge of the coin.

At "noon" you'd see the sun just to the left of the skyring.
At midnight, you'd get a few rays glancing up from below only if you are on the far right side of the ring.

This is how Banksian Orbitals work. They either have enough atmosphere to soak up the rads, or (more likely) he left the Minds to take care of it with their omnipotent powers. (S_J, have you read any Banks?)

[Suicide Junkie]

Its just a simple double-hull idea.

If the water dosen't vaccuum-freeze fast enough to block the hole, you could always pour goop in to make it self-sealing.

Puncture-sealing fluids are advertised all the time these days, for car tires and radiators and whatnot... Just buy some in bulk from Canadian Tire.

If all else fails, pour jello into the outer hull. You could even make the jello armor piece by piece, so you don't have to build the entire outer hull, just a mold for while the jello sets.

[dogscoff]

Suicide Junkie said:
Its just a simple double-hull idea.

If the water dosen't vaccuum-freeze fast enough to block the hole,

When you put it like that, it makes a lot of sense.

you didn't answer my question: Have you read any Iain M Banks stuff? If not, I'd like to repay the man who introduced me to Schlockmercenary by recommending anything by Iain M Banks. It's about the only scifi I enjoy more than Schlock. You'd love "Against a Dark Background" (For the Lazy Guns) but I think a better introduction to his work might be "Excession" or "Use of Weapons". If you lived near me I'd lend you a copy, but I think it would be easier for you to just click http://www.amazon.ca/exec/obidos/sea...015029-1860360 and splurge a few dollars. Trust me, you will not regret it.

Of course if you've already read it all, forget I spoke.

[inigma]

I believe spinning up the astroid would do more harm than good.

At the very least it would do nothing, and at most, it would cause centripetal force to the point that weakens its integrity.

I happen to believe that the 9 hour spin is natural, since gravity is created by the mass of an object, its speed relative to space-time, and the initial alignment of the first atom. I say this because even for Ceres to exist in the first place, it would have had to "settle" into its natural space-time spin, and such a settlement is the lowest-energy result. It would take more energy for it to spin slower, and more mass for it to spin faster.

The best example of this would be to hop on a merry-go-round and have someone toss you a sandbag and for you to bring it to the center of the merry-go-round. As you do, the increased mass equalizes and you spin around much much faster. This is what would happen if you put a large rocket on Ceres to spin it up. But once you remove the rocket, its like throwing the sandbag off the merry-go-round - the mass decreases, and so does the spin. Eventually, as your body returns to the center of the merry-go-round, equilibrium is reached and all that energy you poured into spinning faster was lost to the sandbag you threw off.

If the rocket was ever turned on, though, assuming you could invent the impossible and ensure that the mass you are using to power the rocket wasn't depleted into space as a result (and thus cancel out the effect of the rocket, in a sense, wasting your time), the stability of the merry-go-round would be called into question, and Ceres would fly apart - the natural concequence of adding energy to any object that is already at equilibrium.

So in short: spinning up Ceres would be a physical impossibility because mass is the key ingredient to the gravitational equation.

The best that could be hoped for is some campaign of accreting astroids into it and so increase its mass, but in a controlled manner so as not to obliterate the mass of Ceres that already is stable.

Hollowing out Ceres would more than likely cause Ceres to spin down much slower, to the point that it might even break up entirely. Spinning it up faster to a 1G centriptal force inside a hollowed out band in the core, would probably tear Ceres apart.

The answer would most likely be to find a way to add more mass to Ceres so that 1G centripital could be attained. But then again, if 1G centripital could be obtained, by that point you have enough mass to hold a decent atmosphere and live on the surface.

Except the surface gravity of such a mass would be enough to probably crush you several times over.

[inigma]

Oh and the coin idea would be great, if it weren't such an engineering challenge to create a transparent material strong enough to hold back an ocean of water from flinging into space.

And I don't know if such a boat would float like earth ships, because unlike earth, the deeper in the coin ocean you go, the stronger the centripetal force. I wonder if such a force would practically suck ships down.

Imagine the fish in such an ocean... stuck to the bottom because it takes effort to "climb" up. Swimmers would sink faster than they can float... and boats would have their fishing lines be the straw the breaks the camel's back and starts a chain reation that sucks the whole ship down to the bottom with increasing velocity. Not to mention the force of such a slam on the transparent plating holding in the water.

Sounds like fun!

[Wolfman77]

Give the size, the gravity change (or force acting like gravity) would not be that sudden. also the water would not need to be that deep, there should only be a few percent difference from the surface to the floor. Even if there was a large change, remember that the water is pulled down just as hard as anything in it. The force that keeps us floating (or swimming)is the pressure of the water below is larger than that above. This would still apply, and a more sudden change in force would magnify this, making it harder to get to the outside wall.

[Hunpecked]

If an object's average density is less than water, then it will float in water under one gravity, two, or fifty. However, boat and submarine hulls would be under increased pressure under higher G.